Using XSLT or flowService ?

As part of the implementation of a new project (on webMethods 7.1), we are studying the possibility of performing mappings with XSLT instead of webMethods mappings (flow service or java service).
Would you have any feedback on XSLT compared to flow service, in terms of performance, maintainability, readability ?
I am not convinced that XSLT is appropriate in the case of a mapping with many business rules.

XSLT would not be recommended generally (I’ve never found a reason to use it)… You’re far better off (usually) to create a well thought out flow mapping service that divides up the work (e.g. you don’t want one big mega 1-map step).

Debugging is a pain in XSLT.
Flow services are best in this.

Other product suites like TIBCO BW uses XSLT as the internal mapping engine so the question of XSLT and non XSLT approach does not come but webMethods uses a different approach and hence pros and cons should be evaluated before starting any approach.